1. Field of the Invention
The present invention pertains to the art of multi-compartment refrigerators in which a portion of the air being circulated in one compartment in diverted, through an air passageway formed in a partition wall, into the other compartment and, more particularly, to a system for controlling the temperature in each compartment and the flow of air between the two compartments.
2. Discussion of the Prior Art
In typical household refrigerators having partitioned freezer and fresh food compartments, air is generally circulated over an evaporator and then delivered to both the freezer compartment and the fresh food compartment. Typically, one or more user operated temperature controllers are provided in order to manually adjust the desired temperature ranges for the two compartments. In a common temperature control system, one control member is used for controlling the freezer compartment temperature, while the other control member controls the fresh food compartment temperature. In certain known prior art arrangements, the fresh food control is operatively connected to a thermostat unit that senses the temperature in the fresh food compartment by means of a capillary tube that is connected to the thermostat unit and routed to a predetermined location within the fresh food compartment. With this arrangement, the fresh food control thermostatically maintains the fresh food compartment temperature by periodically energizing and de-energizing a compressor of a refrigeration circuit.
In such a known arrangement, it is also common to connect the freezer control to an air flow damper positioned in the passageway which delivers air from the freezer to the fresh food compartment. As the freezer control is set to a cold position, the damper is moved to allow less air into the fresh food compartment and the fresh food control responds by increasing the active time of the compressor to maintain the temperature in the fresh food compartment and thereby indirectly cools the freezer compartment. Conversely, if the freezer control is set to a less cold position, the damper moves to allow more air to be sent from the freezer to the fresh food compartment and, correspondingly, the fresh food compartment control compensates by running the compressor less often.
Of course, the higher the number of cycles run by the refrigeration circuit over a given time period equates to a higher energy consumption for the refrigerator. It is desirable to provide a temperature control system which can be used to establish the optimal number of operating cycles in order to minimize energy consumption. Unfortunately, a set optimum number of cycles cannot be predetermined as system cycling will depend upon numerous factors, including the environment in which the refrigerator is used, the frequency in which the compartments of the refrigerator are accessed and the size of the refrigerator compartments. Of additional concern is the variance of the cycles over a given time period from one cabinet to the next.
Based on the above, there exists a need in the art for a refrigerator temperature control system which can be used to effectively maintain desired freezer and fresh food compartment temperatures while regulating the refrigeration circuit cycling in the manner which minimizes energy consumption.